version 2
Source: IERS Bulletin A (2000_2000_2)

Orbits: to be used with the IGS Rapid Service Orbits (IGR)

  MJD      Xpole   Ypole  UT1-UTC    LOD  Xsig  Ysig   UTsig  LODsig  Nr Nf Nt
             (10**-6")       (0.1 usec)    (10**-6")    (0.1 usec)  
51646.50   80922  343169  2645232   9121    43    75     122       0   0  0  0
51647.50   82291  343035  2635631  10081  2122  2141    1564       0   0  0  0
51648.50   83582  342842  2625173  10834  4650  4650    4024       0   0  0  0